Armenians (, armentsi) are the fifth largest minority, after Russians, in Bulgaria, numbering 6,552 according to the 2011 census, down from 10,832 in 2001, while Armenian organizations estimate up to 80,000. Armenians have lived in the Balkans (including the territory of modern Bulgaria) since no later than the 5th century, when they moved there as part of the Byzantine cavalry. Since then, the Armenians have had a continuous presence in Bulgarian lands and have often played an important part in the history of Bulgaria from early Medieval times until the present. The main centres of the Armenian community in the country are the major cities Plovdiv (3,140 Armenians in Plovdiv Province in 2001), Varna (2,240 in Varna Province), Sofia (1,672) and Burgas (904 in Burgas Province). The traditional language of the community is Western Armenian, though since education during the Communist period in Bulgaria was in Eastern Armenian, many are also fluent in the latter dialect. Bulgarian, being the official language, is spoken fluently by almost all Armenians in the country. History The Armenians that settled between the 6th and the 11th century in the Rhodopes, Thrace and Macedonia were several thousand in number, mostly Paulicians and Tondrakians and had very strong communal ties. They had very strong ties and influenced the Bulgarian sect of the Bogomils and were later assimilated into it, Bulgarianized and later converted to Roman Catholicism (see Roman Catholicism in Bulgaria) or Islam (see Pomaks). The mother of 11th-century Bulgarian tsar Samuil was the daughter of the Armenian king, Ashot II. Maria, the wife of 10th-century Tsar Peter I, was the granddaughter of Byzantine emperor of Armenian origin, Romanos I Lekapenos. Another Byzantine emperor—Basil I, the founder of the Macedonian dynasty and an Armenian from Thrace—spent his early years as a captive in the First Bulgarian Empire in the 9th century. After both Bulgaria and Armenia were conquered by the Ottoman Empire, many Armenian settlers from Armenia, Crimea, the Polish–Lithuanian Commonwealth and Asia Minor arrived in what is now Bulgaria due to internal migration. Those coming from Armenia were forced to seek a new homeland because of their country's devastation by Arabs, Persians, and Turks. With Bulgaria gaining autonomy in the aftermath of the Russo-Turkish War of 1877-78, many Armenians fled the Ottoman Empire because of the Hamidian massacres in the 1890s and settled in the country, particularly in the major cities of Plovdiv and Varna.